Superoxide dismutase catalyzes the disproportionation of superoxide to hydrogen peroxide and dioxygen. For activity, this exzyme requires one dimetallic Cu,Zn center per subunit. In yeast, the insertion of the copper into superoxide dismutase (Sod1) only occurs in the presence of the copper chaperone protein Lys7. The objective of this proposal is to solve the three dimensional structures of Lys7, with and without the metal ions, and Lys7 complexed with Sod1. In humans, Sod1 has been linked to familial amyotrophic lateral sclerosis (Lou Gehrig's Disease), and a detailed understanding of the mechanism of copper insertion should lead to the development of new therapies for this disease.